1. Field of the Invention
The present invention relates to a driving apparatus and a driving method of a display device, and more particularly, to a driving apparatus with a current storage and duplicating apparatus and a driving method thereof.
2. Description of the Related Art
Traditionally, an organic light-emitting diode (OLED) comprises an organic thin film between its transparent anode and metal cathode. With these film layers, electrons and holes combine in the organic thin film to release energy which converts into visible light. In addition, different organic materials can generate different color lights. By using different organic materials, a full-color display can be manufactured. Generally, advantages of an OLED display include: self-illumination, slim structure, high brightness, high fluorescence efficiency, high contrast, low response time (e.g., in a few microseconds), wide view angle, low power consumption, wide temperature range, and panel flexibility.
Generally, the organic light-emitting diode may be driven by using current for illumination. The amount of currents will determine brightness and color of the OLED. Accordingly, each light-emitting diode needs a driving circuit for controlling the current. The traditional method of controlling the current can be achieved by using switches to control the number of the functioning transistors in a current mirror. For example, a current-type digital-to-analog converter (DAC) uses this method.
FIG. 1 is a schematic drawing showing a prior art OLED display. Referring to FIG. 1, the prior art OLED display 100 comprises a panel 102 and a driving circuit 104. The panel 102 comprises a plurality of matrix-arranged OLEDs 112. The driving circuit 104 comprises a plurality of controllable current sources 114, wherein, each controllable current source 114 is coupled to a corresponding OLED 112. The controllable current source 114 outputs a current to drive the OLED 112 coupled thereto for illumination. The amount of the current determines the brightness and color of the OLED. Accordingly, each OLED 112 requires a controllable current source 114 in the traditional technology.
As described, since each OLED requires a controllable current source, the prior art driving circuit 104 needs a huge area and is costly. In addition, the error of the manufacturing process of the controllable current source also causes high current errors output from it. It is thus desired to develop a method and an apparatus which can reduce the area and cost of the driving circuit, eliminate the current error resulting from the manufacturing process error of the controllable current source, and increase the display efficiency and uniformity of the OLED.